Ok, I just went to play the Sims 3 just now and I got this:

"We are unable to verify that your disc is a valid copy of The Sims 3. Please contact customer service."

It had this error at the top of the box: Disc Authorization Failure.

What's really weird, is that I was playing it like 10 to 15 minutes ago. I tried taking out the copy and putting it back in, but that didn't help. What's going on?

It happens to me sometimes when I download a bunch of custom content at one time. I just restart my computer and it works just fine You should give that a try

I'm having the exact same problem and I haven't even played it yet. If you've figured it out please let me know. Thanks!

Yes, I've had that problem, too. I was told by support to shut down the Mac & turn it back on again. It works fine for me, except when i forget to shut down the Mac before going to sleep.

I have found that there are smudges on my disc when that happens. So after taking it out, and cleaning it with a cloth, it works fine

It just happens,
I try it over and over again even when I take the disc out there are no smudges, nothing it's completely clean and it still won't work and we bought from the store.

This is a common problem I don't know if you have seen this thread about disc authorisation failure but it might help. http://forum.thesims3.com/jforum/posts/list/32201.page

i kept getting the warning and it said there was no disc in the drive, so i uninstalled it and tried to install it again and now its just acting as if there is no disc in there! i cant install it!!
i've gone through so many things to try and fix it nothing is working! i've been looking for viruses and installed stuff that i've been emailed by EA to do, but its not working! its jsut saying there is no disc in there drive, but there really is (i've checked lol)

1Man wrote:Yes, I've had that problem, too. I was told by support to shut down the Mac & turn it back on again. It works fine for me, except when i forget to shut down the Mac before going to sleep.

This is what works for me! I know it's a pain in the butt...

You might also want to relaunch your finder when you finish saving and quitting the game. It will rebuild your desktop and put your icons back in place. I find if I don't relaunch the finder, I have difficulty in shutting my computer off.